Machine for producing milling-cutters.



J. HIGGINSON & H. ARUNDEL. MACHINE FOR PRODUCING MILLING CUTTERS.

APPLICATION FILED NOV, 18. 1916.

Patented May 28, 1918.

2 SHEETS-SHEET L 1 GMWK alnaom J. HIGGINSON & H. ARUNDE'L. MACHINE FOR PRODUCING rvmuws CUTTERS.

APPLICATION FILED NOV- 18. I916.

Patented my 28,11918.

2 SHEETS-SHEET 2.

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mlasmmh 50m, 3 wands Z,

Jiuent 014M Jittom v w a MACHINE FOR PRODUCING MILLING-CUTTERS.

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Specification of Letters Patent.

Patented MayZfi, 191%,

Application filed November 18, 1916. Serial No 132,1 $6.

purpose which shall be; simple in .design and capable. of; relatively. rapid and economic production of the. desired. cutters.

Ourinvention comprises a machine. in which, with :a, tool having a back and; forth movement along; the surface it is cutting, there is. provided a circular movement of the workpiece during the return or-inoperative stroke ofgthe tool, causing thework piece to follow. up. the. tool. asthe latter is withdrawn sothat it meets. another portion. of thework piece on commencing its next. forward or service stroke,

Our invention. further comprises the arrangement whereby, ina machine asbefore specified, the work piece is given forward movement during boththe cutting and return. strokes of the tool, said movement being either a continuous movement or be- .ing interrupted at: the end of each. stroke ofthe tool.

Ourinvention, further comprises the ar rangement whereby, in. a, machine as before specified, thework piece is given a continuous. rotary movement and the .tool hasan oscillatory-movement.through an arc of a circle.

Our. invention further comprises the arrangementwhereby, in a machine as: above specified, the tool. is oscillated through an arc of a circle and the work piece is held stationary duringthe cutting stroke of the tool and is advanced or follows up the tool during its return stroke.

Referring to the twoaccompanying sheets of explanatory drawingsz Figure 1 is an elevation, partly in section, of machine hav ng our in nti n ppli d thereto in one convenient form. a

Fig. 2 is a plan view of the toolfeed gear of the machine shown in Fig. 1.

Fig. 3 is a part sectional end elevation through the work carrying spindle ofthe machine shown in Fig. 1

Figs, 5 and. 6 arediagrammatic views illustrating three modified applications of our invention. i a

The same reference letters. in the different views indicate the same on similar parts,

Referring in the.,first place to Figs, 1, 2 and 3, the workpiece a; (Fig. 3) ismounted upon the. spindle b so that an imaginary vertical linepassing through its. axis always lies beyond or at the extreme limit of the forward traverse of the cutting tool. 0 in the holder (1. also mount a ratchet wheel 0 upon the same. axis as the. work piece a. andprovide two pawl carrying arms 7, with their pawls g, g actuated from a cam or; eccentric it so that they mo ve in unison with the cutting. tool 0. The connecting rod 2'. formed integrally. with the pawl carrying arm f is supported by a collar 3' upon the ratchet wheel 6, wearing blocksJc upon the arms firidingupon such collar. i i

The said pawlcarriers and pawls g are so disposed. that they give the work piece a a rotary movement toward. the cutting tool 0 both when the latter is on. its; operative and its return strokes. On its service. stroke,

when it rotates the work piece, the upper pawl g is pref erably drawn away by therod z" from an. imaginary line passing through -the axis of the work piece and at right angles to a line passing through the axes of the work piece wand of the eccentric it so that it imparts anegative acceleration to the work piece, therate of such acceleration be ing increased by the variation in the angular position of the pawl due to movement about its own pivot. We thereby increase the amount of relief of the milling cutter teeth beyond what would be obtainedif the work piece had a uniform movement.

The tool holder (Z is, fed towardthe work by means of the gear train shown. in Figs. 1 and 2. The pawlm is carriedby an arm n on the toolaslide, the said arm being rocked about the pin. 0 in the fixed bracket p as the slide reciprocates. The ratchet wheel 9 cauSGs the rotation. of the spur wheelsn s, t

u, the latter being on the screw o by trio h, but the cutter being produced has a continuous rotary movement imparted thereto by a pinion w and spur wheel or other gearing. The eccentric it may be rotated by a chain or by spur or other gearing.

In the arrangement shown in Fig. 5, the tool holder d is oscillated through an arc of a circle by the'eccentric h, the said holder being carried in a frame or arm fulcrumed about the pin or the like y. A part a of said frame or arm has a slot therein, into which enters a pin 2 on a pawl carrying arm 3 so that the pawl 9 picks one tooth of the ,ratchetwheel e for each forward movement of the tool holder d. A stop 4: serves as an abutment against which the ratchet wheel teethcan bear during the cutting operation. The pawl spring 5 is preferably sufiiciently strong totend to carry the ratchet wheel backward on its idle or return stroke, so as to insure that a tooth of said ratchet wheel is firm against the stop 4: before the cutter engages the work piece a.

The radius of'movement of the'tool is determined by the configuration of the milling cutter being produced.

With the Fig. 5 arrangement, the work piece is stationary during the operative strokes of the tool 0 but follows up the latter on its'idle or return stroke. Suitable tool feedmg means may be provided for the tool 0.

. In thearrangement shown in Fig. 6, the tool 0 is oscillated by the cam h in the manner similar to that of the Fig. 5 arrangement, but the work piece a has a continuous rotary movement as in the Fig. t arrangementQ Thev rotary movements of the work piece and tool thus combine to produce the required contour of the teeth of the milling cutter.

We do not limit ourselves to any particular details of construction, butmay modify the same within the scope of the appended claims.

It will be seen that the essential of our invention is that the cutting tool moves ap proximately in a plane which is nearly tangential to the peripheral edge of the work piece, the. amount of the defection of said plane'or approximate plane from a tangent being measured by the degree of backing off which is to be imparted to the milling cutter teeth. It will also be seen that in all cases the cutting .tool 0 moves in a line forming an obtuse angle with the radial line of the cutter toothiunder treatment. In pre- I vious practice, rack or bevel wheel teeth have been milled upon the side face of a blank by a cutter moving radially toward the center of the blank, but the latter cannot move simultaneously with the cutter or the return stroke of the cutter after cutting a tooth, for the cutter locks the blank against rotation.

Having now described our invention, what we claim as new, and desire to secure by Letters Patent is 1. A machine for the production of milling cutters by forming teeth around the peripheral edge of a work piece, comprising in combination a work piece with means for rotating the same, a cutting tool, means moving said cutting tool in a plane nearly tangential to the peripheral edge of the work piece, and means causing the work piece to follow up or move simultaneously with the cutting tool as the latter is being withdrawn after a cutting stroke, as set forth.

2. A machine for the production of milling cutters by forming teeth upon the peripheral edge of a work piece, comprising in combination a work piece with means for rotating the same, a cutting tool, a tool carrier, means moving said cutting tool in a means causing the work piece to follow up or move simultaneously with the cutting tool as the latter is being withdrawn after a cutting stroke, as set forth. 3. In a machine for the production of milling cutters, the combination with a tool having a back and forth movement along the surface of and in a direction at right angles to the axis of the work piece it is cutting, of means imparting a circular movement to the said work piece during the cutting and return strokes of the tool, as set forth.

4. In a machine for the production of milling cutters, the combination with a tool having a back and forth movement along the surface of and in a direction at right JOSEPH HIGGINSON. HUBERT ARUNDEL.

Witnesses HILDA Humans, ARTHUR HUGHES.

1 copies ofthis patent be obtained for five cents each, by miilresslng the Commissioner of ratonts,

Washington, D. 0. 

